Nail-biting, scab-picking, and tattooing as nonsuicidal self-injury (NSSI): A deviant case series analysis of the proposed NSSI disorder diagnostic criteria.

ABSTRACT

OBJECTIVE: This study explored the boundaries of the proposed diagnostic criteria for nonsuicidal self-injury disorder (NSSID) as outlined in the Conditions for Further Study section of the Diagnostic and Statistical Manual, Fifth Edition. We sought to falsify the exclusion of certain NSSI behaviors from a diagnosis of NSSID (Criterion D), arguing that these exclusions are inconsistent with the broader phenomenology of the disorder outlined in the other criteria.  METHOD: We describe three case studies involving NSSI (Case 1 scab-picking; Case 2 nail-biting; Case 3 tattooing) that cannot be diagnosed as NSSID because the behaviors are explicitly listed in Criterion D. RESULTS: Despite exclusion as a relevant NSSI behavior per Criterion D, each examined behavior is consistent with the intentionality, functionality, and distress/impairment of NSSID that represent core features of the disorder. CONCLUSION: The case studies presented here suggest that Criterion D should be revised or removed from the NSSID criteria.